A four year review of external quality assessment of sputum AFB smear microscopy centres in Southeast Nigeria.

Abstract

Objective: To identify the types, pattern and trend of errors in sputum smear microscopy in peripheral primary health laboratories in the Southeast States of Nigeria.
Design: Retrospective study
Methods: A retrospective study of laboratory reports of randomly selected and blinded re-checked sputum smear microscopic slides at the peripheral laboratory centres (using Lots Quality Assurance Sampling Method) in the Southeast States of Nigeria between 2003 and 2006.
Result: A total of 862 errors were found between 2003 and 2006 (862/873 or 98.7%), and consisted of HFN 155 (18%), HFP 138 (16%), LFN 161 (18.7%), LFP 186 (21.3%), and QE 222 (25.7%). There was a statistically significant association (P value < .05) between the following types of errors (LFN, QE, total minor errors and total errors) and the period 2003 to 2006. However, there was no statistically significant association between these types of errors and slide volume (microscopic workload). The means of total error, and total minor errors declined as the sampling quarter moved from 1st to the 3rd quarter, while total errors declined as the year moved from 2003 to 2006.
Conclusion: There was a statistically significant relationship between types of errors, pattern of minor errors and period of the study. The study showed a trend between the errors (LFN, QE, and TE) and the period of review (2003 to 2006), while the total minor errors and total errors declined as the sampling quarter moved from 1st to the 4th quarter of the years.

Key Words: External Quality Assessment, Lots Quality Assurance Sampling Method, Nigeria, and sputum smear microscopy.